Određivanje potencijalne amonifikacije u zemljištu metodom sa argininom

In this paper investigations were carried out on two soil types (vertisol and brown forest soil) with different doses of applied N-fertilizer: diameter, N60 N90; N120 and N250. The potential ammonification in soil was obtained by arginine method. The following properties of soil were determined: pH value organic C, available NH4-N and mobile-Al. The pH value in vertisol was 3.75-4.07; mobile-Al was 0.67-4.90 mg/100g; % organic C 1.38-1.46 and the content of available nitrogen was 4.4-11.2 ppm. The amount of released NH4-N by arginine ammonification in this soil type was very low [(-0.12)-0.27mg/g-1h-1]. Correlation coefficients between released NH4-N from arginine and soil pH were (-0.96*), mobile Al - (-0.99**), applied fertilizer doses - (-0.95*). In brown forest soil the amount of released NH4-N by arginine ammonification was greater than in vertisol, ranging from 3.16 to 7.11mg/g-1h-1. Correlation coefficients between soil properties and released NH4-N from arginine were not statistically significant.Cilj ovog rada je bio da se na dva značajna tipa zemljišta Srbije primeni i proveri predložena metoda, kako bi se sagledala kao moguća alternativa za inkubacione metode. U tu svrhu istraživanja su obavljena na dva tipa zemljišta, gajnjača (Mladenovac) i smonica (Kragujevac) u okviru stacionarnih ogleda. Korišćene su varijante ogleda sa rastućim dozama azota djubriva. Odabrane su sledeće varijante ogleda: prečnik, N60, N90, N120 i N250. Uzorci su uzimani sa dubine 0-30 cm u proleće, pre kretanja vegetacije. Na uzetim uzorcima zemljišta primenjena je metoda amonifikacije arginina, kako su predložili Alef i Kleiner (1986). Takodje je u uzorcima zemljišta utvrdjena pH vrednost, sadržaj mobilnog Al, sadržaj organskog ugljenika i sadržaj pristupačnog NH4-N. Na osnovu dobijenih rezultata (smonica) ne može se preporučiti korišćenje metode sa argininom kod zemljišta čija svojstva imaju direktan negativan uticaj na aktivnost mikroorganizama (niska pH vrednost, visok sadržaj mobilnog Al). Mogli bi da zaključimo na osnovu naših rezultata (za gajnjaču) da je približna granica pH vrednosti zemljišta ispod koje ovu metodu ne treba primenjivati 4,00 (nKCl). Na kraju kod primene ove metode obavezno se mora voditi računa o sadržaju pristupačnog NH4-N u zemljištu

Određivanje potrebnih količina đubriva za pšenicu

In this experiment we used brown forest soil that has been used in long-term experiments, for 30 years, with increasing doses of introduced nitrogen fertilizer in variants. In order to determine the quantities of nitrogen fertilizer required for wheat, a calculation model has been applied. This calculation requires not only a reliable method for determining soil nitrogen availability (both the total and easily hydrolyzed nitrogen method were used), but also a reliable method for determining the coefficient of nitrogen utilization from soil as well as data on the coefficient of nitrogen utilization from fertilizer (Nani) for the added quantities of nitrogen fertilizer.Cilj ovog istraživanja je bio da se na osnovu utvrđene pouzdanosti za ocenu pristupačnosti azota zemljišta (ukupni i lakohidrolizujući azot) primeni i proveri predloženi model za utvrđivanje količine azota đubriva koju treba uneti u zemljište za planirani prinos. Istraživanja su obavljena na gajnjači koja se koristi u okviru stacionarnog ogleda sa određenim sistemom đubrenja i plodoredom već 30 godina. Za određivanje potrebnih količina đubriva za pšenicu, primenjen je model obračuna za koji je potrebno utvrditi: pouzdanu metodu za ocenu pristupačanosti zemljišnog azota, na osnovu koje se određuje koeficijent iskorišćenja azota iz zemljišta, zatim koeficijent iskorišćavanja azota iz đubriva i vrednost aktiviranog azota zemljišta za unetu količinu azota đubriva. Korišćena vrednost koeficijenta iskorišćavanja azota iz đubriva za uslove koji vladaju u gajnjači je bio 50%, pri obračunu za prihranu pšenice i 43,3% za obračun potrebnih količina đubriva za ceo vegetacioni period. Na osnovu obavljenih istraživanja može se zaključiti da je prosečna vrednost aktiviranog azota zemljišta bila 4,5 kgN/ha na dodatih 10 kgN/ha azota đubriva. Za metode ukupnog i lakohidrolizujućeg azota, koje su korišćene za predloženi model, odnosno obračun (prihrana) i za koje je utvrđena pouzdanost, razlike između količina azota đubriva koje treba primeniti po predloženom modelu i stvarno primenjenih količina đubriva na stacionarnom ogleda su minimalne i bile su u granicama od 1,34-5,63 kgN/ha. Za metodu lakohidrolizujućeg azota, koja je korišćena za predloženi obračun potrebnih količina azota đubriva za ceo vegetacioni period za pšenicu, razlike između količine azota đubriva koje treba primeniti pri setvi i za prihranu, po predloženom modelu i stvarno primenjenih količina su takodje bile minimalne i to u granicama od 0,4-18,95 kgN/ha. Ovi rezultati u potpunosti potvrđuju tačnost, odnosno vrednost predloženog modela, ali i pouzdanost navedenih metoda za ocenu pristupačnosti azota zemljišta

Does art expression help mood regulation?

Umjetnost je prirodni i senzorni način ekspresije jer uključuje dodir, miris i druga osjetila unutar umjetničkog iskustva. Umjetničko izražavanje može dati značenje iskustvima ili razriješiti negativne emocije tako pružajući neku vrstu olakšanja i načina reguliranja emocija. U kontekstu korištenja umjetnosti u poboljšanju raspoloženja i izražavanju emocija, valja istaknuti procese regulacije emocija poput preusmjeravanja pažnje jer je upravo umjetničko izražavanje ono na što se može usmjeriti pažnja. Osnovica ovog procesa jest mogućnost odabiranja usmjeravanja pažnje na željeni aspekt situacije čime je moguće promijeniti emocionalni doživljaj. Isto tako ekspresija negativnih emocija je strategija na kojoj se bazira ideja da umjetnost može pomoći u ublažavanju emocionalne boli ili napetosti. S obzirom na dosadašnje rezultate istraživanja likovnog izraza i raspoloženja te njihove nedostake, cilj ovog istraživanja je bio utvrditi utjecaj različitih zadataka likovnog izražavanja na promjene u raspoloženju. U istraživanju je sudjelovalo 64 ispitanika raspoređenih u četiri grupe. Svim ispitanicima je inducirano negativno raspoloženje putem video isječka nakon čega im je izmjereno raspoloženje PANAS skalom. Zatim se jedna grupa likovno izražavala o tome što su doživjeli tijekom gledanja video isječka (ekspresija; N=16), druga o tome što je za njih sreća (pozitivna distrakcija; N=16), treća je crtala objekt (neutralna distrakcija; N=16), a četvrta grupa je rješavala labirinte (kontrola; N=16). Svim ispitanicima je ponovno izmjereno raspoloženje. Rezultati su pokazali značajno poboljšanje raspoloženja u pozitivnom afektu u grupi pozitivne distrakcije u odnosu na ekspresivnu grupu i grupu koja se nije likovno izražavala. Utvrđeno je i značajno poboljšanje raspoloženja u negativnom afektu kod grupe neutralne distrakcije u odnosu na grupu koja se nije likovno izražavala. Nije utvrđena promjena između pozitivnog i negativnog raspoloženja unutar grupa koje su se likovno izražavale. Korišteno kao distrakcija, likovno izražavanje se pokazalo najefikasnijim za poboljšanje raspoloženja u odnosu na ostale zadatke. Kvalitativna analiza uradaka je pokazala sadržajne razlike između ekspresivne grupe i grupe pozitivne distrakcije s obzirom na različite kriterije uradaka (apstraktnost/konkretnost, isticanje boja, stupanj uloženog truda, kvaliteta linije, zrelost, složenost, ispunjenost papira i izražavanje emocija).Art is a natural and sensory way of expression because it includes touch, smell and other senses as a part of an artistic expression. Artistic creation can give meaning to experiences or express negative emotions giving a person a sense of relief or a way to regulate emotions. In the context of using art as mood regulaton and emotion expression, it is important to mention emotion regulation strategies such as distraction because artistic expression can be an act to shift our attention to. At the basis of this process is the possibility of shifting attention to a more inviting aspect of a certain situation which leads to a change in emotions or mood. Also, strategies such as expression of negative emotions are based on the idea that art expression can help us in releasing or venting emotional pain and discomfort. Considering previous research results on art expression and mood and their shortcomings, the aim of this study was to determine the effect of different art tasks on mood. Participants in this study (N=64) were distributed into four groups. Negative mood was induced to all participants with a short video after which it was measured with PANAS scale. Subsequently, the first group produced artwork on what they experienced while watching the video (expression), the second group produced artwork on what makes them happy (positive distraction), the thrid group drew an object (neutral distraction) and the fourth group solved a labyrinth task (control). Participant's mood was measured again. Results have shown significant mood improvement in the positive affect within the positive distraction group oppose to the expressive and non-art group. Significant mood improvement in the negative affect was detected within the neutral distraction group oppose to the non-art group. There was no change in positive and negative mood within each of the art task groups. Used as a distraction, art expression was shown to be the most effective mood improvement acivity in relation to all the other tasks. Qualitative analysis has shown content differences between the artworks produced in the expression group and positive distraction group in relation to different artwork criteria (abstract or concrete content, prominence of color, implied energy, line quality, developmental level, complexity and space)

Aerobna i anaerobna inkubacija - biološki indeksi pristupačnosti azota zemljišta

Our researches have been made on brown forest soil that had been used in long-term experiments set up according to specified fertilization system for over 30 years. We have chosen those experiment variants in which quantities of nitrogen fertilizers were gradually increased. The soil samples taken from 0 cm to 30 cm depth were used to determine biological indexes of nitrogen availability (aerobic and anaerobic incubation). The same samples were also used for pot experiments with oat. Plant and soil parameters obtained in controlled conditions were used for determination of biological indexes reliability in measuring the soil nitrogen availability. On the grounds of correlation analysis, it can be concluded that biological index of nitrogen availability achieved by the anaerobic incubation (without substraction of the initial content of available nitrogen) of the investigated brown forest soil is the reliable indicator of soil nitrogen availability. That is not the case with the aerobic incubation in which reliability has not been established.Istraživanja su obavljena na gajnjači (Mladenovac) koja se koristi u okviru dugogodišnjeg stacionarnog ogleda, sa određenim plodoredom i sistemom đubrenja već više od trideset godina. Za ova istraživanja odabirane su varijante ogleda gde je primenjena rastuća doza azota đubrenja. Za utvrđivanje bioloških indeksa pristupačnosti azota primenjene su aerobna i anaerobna metoda sa dva različita načina obračuna rezultata (sa oduzimanjem i bez oduzimanja početnog sadržaja pristupačnog azota). Radi određivanja parametara biljaka i zemljišta koji su vrednovali pouzdanost korišćenih metoda za ocenu pristupačnosti azota zemljišta izveden je ogled u kontrolisanim uslovima uz primenu izotopski obeleženog azota (15N). Na osnovu urađene korelacione analize odnosno utvrđene korelativne zavisnosti između bioloških indeksa i parametara biljaka i zemljišta može se zaključiti da se biološki indeks koji je utvrđen anaerobnim postupkom bez oduzimanja početnog sadržaja pristupačnog NH4 može smatrati pouzdanim za ocenu pristupačnosti azota zemljišta. Pouzdanost nije utvrđena za aerobnu metodu (sa oduzimanjem i bez oduzimanja početnog sadržaja pristupačnog azota) kao i za anaerobni postupak sa oduzimanjem početnog sadržaja pristupačnog NH4-N

Monitoring of middle cerebral arteries with transcranial Doppler during the performance of cgnitive tasks : gender differences

Transkranijska Doppler ultrasonografija (TCD) je neinvazivna dijagnostička metoda kojom možemo pratiti promjene brzina strujanja krvi (BSK) u cerebralnim arterijama te na taj način procijeniti lokalnu metaboličku aktivnost moždanog tkiva. Dosadašnja istraživanja utvrdila su korelaciju mentalne aktivnosti prilikom rješavanja određenih kognitivnih zadataka s povećanjem protoka krvi kroz srednje cerebralne arterije (MCA). Naše istraživanje uspoređivalo je BSK u MCA između zdravih mladih muškaraca i žena tijekom izvođenja dva kognitivna zadataka (testa verbalne fluentnosti (VFT) te Stroop testa s nekongruentnim podražajem). U ispitivanje je uključeno 18 dobrovoljaca (7 muškaraca i 11 žena). BSK mjerene su istovremeno u obje MCA kroz transtemporalni koštani prozor. Nađeno je statistički značajno povećanje BSK kod muškaraca i žena prilikom izvođenja oba kognitivna zadatka. Prilikom izvođenja oba zadatka nije pronađena statistički značajna razlika u BSK u MCA između spolova, niti je pronađena statistički značajna razlika u BSK između lijeve i desne MCA u pojedinog spola.Transcranial Doppler ultrasonography (TCD) is a noninvasive diagnostic method that enables monitoring of blood flow velocity (BFV) changes in the cerebral arteries and thereby to assess local metabolic activity of brain tissue. Previous studies have established a correlation between mental activity during cognitive tasks performance and increasing BFV through the middle cerebral arteries (MCA). The aim of our study was to compare BFVs in the MCA between healthy young men and women during the performance of two cognitive tasks (verbal fluency test (VFT) and the Stroop test with incongruent stimuli). The study included 18 volunteers (7 men and 11 women). BFVs were measured simultaneously in both MCA through transtemporal bone window. A statistically significant increase in BFV was found in men and women during the performance of both cognitive tasks. No statistically significant gender differences in BFVs were found during cognitive tasks performance. Additionally, no statistically significant difference in BFV between the left and right MCA was found in females or males

Transformacija azota u kiselim zemljištima pri promeni pH vrednosti

The aim of this investigation was to determine which application of fertilizer and lime material does not form toxic quantities of nitrite nitrogen and when the losses by denitrification are the lowest in the examined acid soils. Investigations were performed on pseudogley soils of different acidity. Changes of available nitrogen forms were examined by the method of short-term incubation experiments. Experimental treatments were without the use of mineral fertilizers and with application of (NH4)2SO4 (100 ppm of NO3-N) and KNO3 (100 ppm of NO3-N); with and without addition of Ca(OH)2 (50% of full neutralization and full neutralization). When (NH4)2SO4 was used, nitrites occurred in both examined soils as a result of decelerated nitrification and when KNO3 was added as a result of chemical denitrification. Application of Ca(OH)2 caused the intensification of mineralization, nitrification and biological denitrification processes. When a higher dose of lime material was used (full neutralization), nitrites occurred in larger quantities as a result of the strengthening of nitrification and denitrification processes. Application of a lower lime dose caused nitrite occurrence in smaller quantities. Therefore, in these soils as well as in soils of similar chemical properties, application of lower doses of lime material can be recommended ( lt 50% of full neutralization) as well as the application of ammonium fertilizer, bearing in mind that in such conditions losses of added fertilizer in the denitrification process are reduced and the occurrence of nitrites as an intermediate product of this process is prevented.Istraživanja su obavljena na pseudoglejnom zemljištu različite kiselosti. Cilj ovih istraživanja je bio da se utvrdi pri kojoj primeni đubriva i krečnog materijala se ne obrazuju toksične količine nitrita i kada su gubici azota denitrifikacijom najmanji. Primenom amonijum sulfata, kod oba ispitivana zemljišta, obrazovali su se nitriti kao posledica usporene nitrifikacije a pri dodatku kalijum nitrata nitriti su nastajali usled biološke i hemijske denitrifikacije. Pri primeni viših doza Ca(OH)2 (puna neutralizacija) nitriti su se javljali u većim količinama kao rezultat jačanja procesa nitrifikacije i denitrifikacije, dok je pri nižim dozama krečnog materijala količina obrazovanih nitrita bila manja. Radi sprečavanja pojave nitrita i smanjenja gubitaka azota procesom denitrifikacije, kod ovakvih i zemljišta sličnih hemijskih svojstava, može se preporučiti primena amonijačnih đubriva i upotreba nižih doza krečnog materijala

Monitoring of middle cerebral arteries with transcranial Doppler during the performance of cgnitive tasks : gender differences

Transkranijska Doppler ultrasonografija (TCD) je neinvazivna dijagnostička metoda kojom možemo pratiti promjene brzina strujanja krvi (BSK) u cerebralnim arterijama te na taj način procijeniti lokalnu metaboličku aktivnost moždanog tkiva. Dosadašnja istraživanja utvrdila su korelaciju mentalne aktivnosti prilikom rješavanja određenih kognitivnih zadataka s povećanjem protoka krvi kroz srednje cerebralne arterije (MCA). Naše istraživanje uspoređivalo je BSK u MCA između zdravih mladih muškaraca i žena tijekom izvođenja dva kognitivna zadataka (testa verbalne fluentnosti (VFT) te Stroop testa s nekongruentnim podražajem). U ispitivanje je uključeno 18 dobrovoljaca (7 muškaraca i 11 žena). BSK mjerene su istovremeno u obje MCA kroz transtemporalni koštani prozor. Nađeno je statistički značajno povećanje BSK kod muškaraca i žena prilikom izvođenja oba kognitivna zadatka. Prilikom izvođenja oba zadatka nije pronađena statistički značajna razlika u BSK u MCA između spolova, niti je pronađena statistički značajna razlika u BSK između lijeve i desne MCA u pojedinog spola.Transcranial Doppler ultrasonography (TCD) is a noninvasive diagnostic method that enables monitoring of blood flow velocity (BFV) changes in the cerebral arteries and thereby to assess local metabolic activity of brain tissue. Previous studies have established a correlation between mental activity during cognitive tasks performance and increasing BFV through the middle cerebral arteries (MCA). The aim of our study was to compare BFVs in the MCA between healthy young men and women during the performance of two cognitive tasks (verbal fluency test (VFT) and the Stroop test with incongruent stimuli). The study included 18 volunteers (7 men and 11 women). BFVs were measured simultaneously in both MCA through transtemporal bone window. A statistically significant increase in BFV was found in men and women during the performance of both cognitive tasks. No statistically significant gender differences in BFVs were found during cognitive tasks performance. Additionally, no statistically significant difference in BFV between the left and right MCA was found in females or males

Biological indices of soil organic matter in long term fertilization experiment

Dynamics of labile fractions of soil organic matter under 36-years of application of mineral and organic fertilizer in Chernozem (Mollisol) in Ukraine were studied. "Light" fractions of SOM between various mineral and organic fertilization treatments were studied. Amount of total organic C increased in manured treatments; while amount of total N didn't change under any of the treatments. Labile N was correlated to soil mineral N, MBC and MBN, LFN and LFC, while labile C correlated to the total organic C, LFC and LFN. The pattern of mineralization and accumulation of SOM suggested that OC dynamics more related to long-term substrate addition, while N dynamics better reflects short-term substrate addition. Application of mineral fertilizer alone accelerated mineralization of SOM, especially of "light" fraction, while partial or complete replacement of inorganic by organic fertilizers has a significant impact on soil microbial community and soil capability to supply plants with nutrients for longer period

Reakcija genotipova kukuruza na uslove gajenja

Studies on the effects of sowing densities on maize grain yields under irrigation were performed with the aim of creating favourable conditions for plant growth and development, under which the genetic yield potential would be maximally exploited. A two-factorial trial was performed in the period 2006-2009 on chernozem, according to the split- plot method with four replicates. Four maize hybrids of different FAO maturity groups (ZP 341, ZP 434, ZP 684 and ZP 704) were observed in combination with seven sowing densities (G1 - 40,816 plants ha-1, G2 - 50,125 plants ha-1, G3 - 59,524 plants ha-1, G4 - 69,686 plants ha-1, G5 - 79,365 plants ha-1, G6 - 86,286 plants ha-1 and G7 - 98,522 plants ha- 1). The obtained results showed statistically very significant differences in maize grain yields between the studied hybrids and the sowing densities. The lowest yields were recorded for all studied hybrids at the lowest sowing density (40,816 plants ha-1). The regression analysis indicated that, depending on a maize hybrid, the following maximum yields could be expected: ZP 341 - 13.25 t ha-1 at a sowing density of 81,000 plants ha-1, ZP 434 - 13.00 t ha-1 at a sowing density of 75,000 plants ha-1 , ZP 684 - 13.83 t ha-1 at a sowing density of 82,000 plants ha-1 and ZP 704 - 12,83 t ha-1 at the sowing density of 77,000 plants ha-1. In accordance with the rational use of seeds, high yields are obtained by sowing that provides 50,000 plants of ZP 434 ha-1, 60,000 plants of ZP 341 ha-1 and ZP 704 ha-1 and 70,000 plants of ZP 684 ha-1.U cilju stvaranja povoljnih uslova za rast i razviće biljaka, pri kojima se maksimalno koristi genetički potencijal rodnosti, obavljena su proučavanja uticaja gustine setve na visinu prinosa zrna kukuruza gajenog u navodnjavanju. Dvofaktorijalni ogled izveden je u periodu 2006-2009 na černozemu, po metodi razdeljenih parcela u četiri ponavljanja. Ispitivano je četiri hibrida kukuruza različite FAO grupe zrenja (ZP 341, ZP 434, ZP 684 i ZP 704) u kombinaciji setve sa sedam gustina (G1 - 40000 bilj.ha-1, G2 - 50000 bilj.ha-1, G3 - 60000 bilj.ha-1, G4 - 70000 bilj.ha-1, G5 - 80000 bilj.ha-1, G6 - 90000 bilj.ha-1, G7 - 100000 bilj.ha-1). Dobijeni rezultati pokazuju da su između ispitivanih hibrida i gustina setve ostvarene statistički veoma značajne razlike prinosa zrna kukuruza. Svi ispitivani hibridi najniže prinose su ostvarili pri najmanjoj gustini setve, sa 40.000 bilj.ha-1. Regresiona analiza pokazuje da se zavisno od hibrida kukuruza mogu očekivati sledeći maksimalani prinosi zrna: ZP 341 - 13,25 tha-1 pri gustini setve 81.000 bilj.ha-1, ZP 434 - 13,00 tha-1 pri gustini 75.000 bilj.ha-1 , ZP 684 - 13,83 tha-1 pri gustini 82.000 bilj.ha-1 i ZP 704 - 12,83 tha-1 pri 77.000 bilj.ha-1. U skladu sa racionalnom upotrebom semena, visoki prinosi se dobijaju setvom koja obezbeđuje po hektaru 50.000 biljaka hibrida ZP 434, zatim 60.000 biljaka hibrida ZP 341 i ZP 704 i 70.000 biljaka ZP 684

How Irrigation Water Affects the Yield and Nutritional Quality of Maize (Zea mays L.) in a Temperate Climate

Soil water deficit has an adverse effect on crop productivity and is one of the main limiting factors of global food security. Field experiments were conducted in Vojvodina, Serbia, to expand and improve knowledge about the effects of different levels of irrigation on maize grain yield and quality. The studied irrigation treatments were: full irrigation (I-100), 75% (I-75) and 50% (I-50) of I-100, and no irrigation (I-0)-rainfed. The irrigation level affects maize grain yield; protein, starch, and oil content; and mineral composition. The results show that that yield decreases with increasing water deficit in three study years. On average, full irrigation results in the highest oil content and rainfed conditions in the lowest. The starch content increases and the oil content decreases with decreasing irrigation. Irrigation significantly increases the concentrations of K, Mg, Fe, Mn, and Zn, and reduces the Ca concentration compared to the rainfed treatment. A 25% water deficit (I-75) has a positive effect on certain maize grain nutrients and the yield is significantly reduced. The highest grain yield and oil content are achievable with full irrigation. For good nutrientional quality of maize, treatment I-75 can be proposed under similar soil and climate conditions